Registry mechanism for printing units

ABSTRACT

A coupling mechanism between a printing unit and a drive shaft which powers a number of adjacent printing units acting upon the same web of paper having a drive gear adjustable in phase position. To obtain such adjustment, first and second sleeves are provided on the shaft having meshing helical splines. The first sleeve slidably keyed to the shaft, has a yoke for adjusting its axial position, thereby to change the degree of engagement of the helical splines and the phase position of the drive gear. The yoke is in the form of a threaded collar encircling the first sleeve and axially movable by means of a captive nut. The second sleeve has a shiftable yoke which positions the drive gear in meshing engagement with the driven gear and which permits retraction of the drive gear for declutching and timing purposes.

United States Patent Tafel Feb. 15, 1972 [54] REGISTRY MECHANISM FOR2,418,555 4/1947 Kirsten ..74/417 X PRINTING UNITS FOREIGN PATENTS 0RAPPLICATIONS [72] Lma'd La Grange 537,291 10/1931 Germany ..101/248 [73]Assignee: North American Rockwell Corporation, 151,391 8/ 1955 Sweden101/248 Pittsburgh, Pa. Primary Examiner.l. Reed Fisher [22] mmAttorney-Wolfe, Hubbard, Leydig, v01: & Osann, Ltd.

[21] Appl. N0.: 44,246

ABSTRACT 521 US. Cl ..10l/18l, 101/248 A p i mechanism between p g d adrive 511 1111.01. .3411 13/14 Shaft whlch Powers a number of i t p s yes 1581 Held of Search 101/248, 181, 183, 180, 174, "P the i web of Paphaving a dnve gear adjustable m 101/177, 178, 136, 138, 139, 140, 182,184, 216, phase position. To obtain such ad ustment, first and second29; 74/395 400, 402 sleeves are provided on the shaft having meshinghelical splines. The first sleeve slidably keyed to the shaft, has ayoke 56] References Cited for adjusting its axial position, thereby tochange the degree of engagement of the helical splines and the phaseposition of the UNITED STATES PATENTS drive gear. The yoke is in theform of a threaded collar encircling the first sleeve and axiallymovable by means of a captive 2,893,310 7/1959 Johnson ..101/248 X mmThe second Sleeve has a shiftable yoke which positions 2539068 1/195 1Funk "101/248 the drive gear in meshing engagement with the driven gearand S which permits retraction of the drive gear for declutching andangs on e timin u ses. 1,850,800 3/1932 Langston et al. .....101/24s gprpo 2,755,686 7/1956 Bade ..74/417 X 5 Claims, 3 Drawing FiguresPATENTEI] FEB 15 I972 SHEET 1 OF 3 REGISTRY MECHANISM FOR PRINTING UNITSIn printing presses, for example, presses of the perfecting lithographictype, intended for simultaneously printing on opposite sides of acontinuous web, are made up of a plurality of printing units arrangedside by side for acting in succession on the web and all driven by asingle longitudinal drive shaft. In order to insure proper registrationbetween successive printed impressions, particularly in multicolorprinting, it is essential to have the printing cylinders perfectlyphased with the printed impressions on the web. Approximate phasing canbe achieved by declutching, that is, by unmeshing the gears between thedrive shaft and the cylinders and remeshing them in approximate phaseposition. However, for procuring precise register and for making minorrunning adjustments from time to time, it is necessary to provide meanswhich permit' a fine continuous and precise adjustment in phasingbetween the shaft and the gears which are driven by the shaft.

it is an object of the present invention to provide improved means foradjusting the phase position of the drive gearing for a printing unitwith respect to the drive shaft which powers a number of cooperatingpress units all acting upon a single web of paper. It is a more specificobject to provide an adjustable coupling of novel construction betweenthe drive shaft and a drive gear thereon which permits gross changes inphase position by unmeshing the gears and remeshing them in a newposition as well as continuous fine adjustment in phase position asrequired, for example, where impressions of different color must beoverprinted in precise register with one another.

It is another object of the present invention to provide a couplingbetween a drive shaft and the cylinders of a printing unit which permitsfine changes in registry to be made, and maintained, without necessityfor stopping the press.

It is another object of invention to provide a phase-adjusting couplingfor a printing unit which includes a pair of sleeves having a helicalsplined connection between them and in which the degree of splineengagement determines the relative phasing between the drive gear andthe shaft upon which it is mounted. It is a related object to provide acoupling in which the sleeve which transmits the output torque issubject to end thrusts which cancel one another, permitting such sleeveto be maintained in position with relatively light mechanism andutilizing only light control forces.

It is another object of the present invention to provide a registeradjusting arrangement including a positioned sleeve keyed to the driveshaft under the control of a positioning yoke of simple collarconstruction which is nonrotatable and which is threaded for movement bya nut for effecting extremely small changes in sleeve position in onedirection or the other.

It is more specifically an object of invention to provide a phaseadjusting mechanism in which the same helical splines which bring aboutsmall changes in phase are utilized in the declutching movementnecessary for freeing the gears to achieve gross changes in phaseposition.

It is a general object of the invention to provide a phase adjustingarrangement for units of a printing press which is of simple andeconomical construction, which may be easily operated with the driveshaft and press cylinders in motion, which has a minimum number ofbacklash points and minimum windup, and which is capable of holding theadjustment for long press runs without any care or attention on the partof the operator.

Other objects and advantages of the invention will become apparent uponreading the attached detailed description in which:

FIG. 1 is an elevational view, in partial section, showing a press unithaving a phase-adjustment coupling constructed in accordance with thepresent invention and showing portions of the adjacent press units.

FIG. 2 is a vertical enlarged section taken through the phase-adjustingcoupling in FIG. 1.

FIG. 3 is a simplified transverse section looking along line 3-3 in FIG.2.

FIG. 4 is a fragmentary view, enlarged as compared to FIG. 1, andshowing the clutch control member.

FIG. 5 is an enlarged perspective view of the first adjustable sleevewhich forms a part of the assembly.

While the invention has been described in connection with a preferredembodiment, it will be understood that I do not intend to be limited tothe particular embodiment shown but intend, on the contrary, to coverthe various alternative and equivalent constructions included within thespirit and scope of the appended claims.

Turning now to FIG. 1, there is disclosed a printing unit 10 forming apart of a perfecting lithographic press and with adjacent, similar unitsll, 12 all of which simultaneously print on opposite sides ofa paper web13. The printing unit is of boxy construction having end frames 21, 22in which the cylinders and rollers are joumaled, and side frames 23, 24.For printing the upper surface of web 13 a plate cylinder 31 applies aninked impression to a blanket cylinder 32, with the ink being fed to theplate cylinder by an ink system 33, and with water being furnished by adampening system 34. Similarly, for printing the underside of the web13, a plate cylinder 35 applies an inked impression upon a blanketcylinder 36, the ink and water systems being indicated at 37, 38,respectively. The blanket cylinders 32, 36, arranged in opposition, actas impression cylinders for one another. The cylinders 31, 32 and 35, 36will be understood to be geared together by the usual helical gears (notshown), the blanket cylinder 32 being powered by a driven gear, in theform of a spiral bevel-type gear 39.

As is usual in printing presses employing multiple units, a singlehorizontal drive shaft 40 is drivingly coupled to all of the units.Conveniently, the drive shaft is broken into sections by couplings 41,42, a typical section being joumaled in bearings 43, 44.

In accordance with the present invention a first, or outer, sleeve and asecond, or inner, sleeve are provided on the drive shaft 40, the sleeveshaving interengaging helical splines, with the first sleeve beingslidably keyed to the drive shaft with provision with endwise adjustmentand with the second sleeve carrying a helical bevel-type gear havingmeans for holding the same in mesh with the driven spiral gear 39connected to the press cylinders. In the present embodiment the firstsleeve, indicated at 50, is keyed to the shaft by a key 51 which isslidably engaged by the walls of an axial groove 52 formed inside of thesleeve (see FIG. 4). At its right-hand end, the sleeve has a set ofsplines 53, which are helically formed. Surrounding the sleeve 50 is asecond sleeve 55 having a set of internal helically formed splines 56.The sleeve 55 is secured, by a ring of screws 57, to a collar 58 whichis integral with a helical bevel-type drive gear 59 which is snugly butfreely slidable with respect to the outer surface of the shaft 40.

In FIG. 2, the drive gear 59 is shown in two separate posi tions, in afirst or dot-dash position in which the gear is in mesh with the drivengear 39, and a second or retracted position in which the gear 59 isretracted out of mesh with the driven gear 39. For the moment, it willbe assumed that the drive gear 59 occupies its meshed position, andmention will be made in due course of the means for holding the drivegear in meshed position.

Further in accordance with the invention, a positioning yoke is providedfor engaging the sleeve 50 for adjusting the axial position of thesleeve with respect to the shaft and hence the degree of engagement,under running conditions, of the helical splines 53, 56, the yoke beingin the form of a nonrotatable hub or collar threaded for axial movement,in one direction or the other, by a captive nut. Thus, referring to FIG.2, the yoke indicated at 60 is slidably mounted in a cylindrical bushing61 having a smooth cylindrical inner surface 62, and a mounting flange63 which is secured to the wall 23 of the press by a circle of mountingscrews 64. In order to prevent rotation of the yoke 60, a key isprovided in the form of a pin 65 which penetrates an opening 66 in thebushing to extend into an axial groove 67 formed in the outer wall ofthe member 60.

To provide coupling between the yoke 60 and sleeve 50, a bidirectionalthrust bearing is provided in the form of a pair of opposed rollerbearings 71, 72. The first bearing 71 has an outer race which is seatedin a groove formed in the yoke and an inner race which abuts against thepresented ends of the splines 53 on the sleeve. The opposed bearing 72has an outer race which is seated in the yoke and an inner race which isclamped in place by a nut 73 engaging a thread 74 formed on theleft-hand end of the sleeve. The clamping nut serves to remove anyendwise play between the yoke and the sleeve, while the bearingsaccommodate the relative rotation.

For the purpose of adjusting the yoke 60 endwise, the yoke is provided,at its left-hand end, with a screw thread 80 which is engaged by acaptive nut 81. The nut, which is of circular shape, is held captive bya flanged ring 82 which is secured to the nut by a series of machinescrews 83. The flange on the ring, indicated at 84, forms an internalannular groove which receives and mates with, a flange 85 integrallyformed on the bushing 63. For the purpose of rotating the circular nut81 it carries, about its periphery, gear 86 which meshes with anadjusting pinion 87 having a shaft 88 which is coupled to someconvenient setting means.

For the purpose of preventing entry of foreign matter along the shaftand into the bearings 71, 72, an annular end cap 90 is provided, held inplace by a circle of screws 91 which are tapped into the end of the yoke60. Lubrication is fed to the bearings 71, 72 via alined openings 92,93, 94.

It will be apparent, then, assuming that the drive gear 59 is held inits reference meshing position with respect to the driven gear 39, thatrotation of the nut 81, which is axially captive, will result inrelative axial movement of the yoke 60, precisely accompanied bymovement of the sleeve 50. The resulting change in the degree or depthof engagement between the splines 53, 56 causes the sleeve 55, and thedrive gear 59 which is connected to it, to undergo slight rotationalmovement relative to the shaft 40, thereby changing the phase positionof the drive gear 59 with respect to the shaft. This, in turn, resultsin a slight change in phase of the driven gear 39 and a correspondingchange in phase of the plate on the plate cylinder. This, in turn,slightly changes the location of the inked impression on the cooperatingblanket cylinder so that the inked impression imparted to the web 13 isslightly advanced or retarded with respect to the other inkedimpressions on the web which are made in the other units of the press.Since movement at the periphery of the nut is related to axial movementof the yoke 60 by a large factor which may, in a practical case, be onthe order of 8:1, a highly precise and continuous adjustment in registrymay be made, with any desired degree of precision. And, once set, thereis little tendency for the phase relationship to change unless and untilintentionally changed by rotation of the nut.

In accordance with one of the aspects of the present invention, meansare provided for not only holding the drive gear 59 in precise meshingposition with respect to the shaft 40 but also for retracting the drivegear into a declutched position, with the retracting movement beingaccommodated by the same splines 53, 56 which are utilized to achievethe precise phase adjustment. Thus, referring to FIGS. 2 and 3, ashifting yoke is provided for the sleeve 55 for causing the sleeve, andthe drive gear 59 which it carries, to be positively positioned ineither one of its two extreme positions. The yoke, indicated at 100, isin the form of a ring which extends around the sleeve 50 and which hasan interposed ball bearing 101, the races of the bearing being axiallycaptive in the sleeve and ring, respectively. For shifting the ring 100between its running and retracted positions, a shifting mechanism isprovided consisting of a pair of levers 103, 104 centrally pivoted at105, 106, respectively, and coupled, at the upper ends, to trunnion pins107, 108 mounted on the ring. The lower ends of the levers 103, 104 areslotted as indicated at 111, 112 for reception of aligned eccentrics113, 114 formed on a throw shaft 115. The shaft is journaled in blocks116. 117, with a throw arm 118 secured to the forward end of the shaft.The phasing of the eccentrics is such that when the throw arm is in itsdownwardly extending position (FIG. 4) the sleeve 55 and its drive gear59 are disengaged as shown in FIG. 2, but when the arm 118 is rotatedaround into its upwardly extending or clutch-engaged position, therocking of the levers 103, 104 moves the ring 100, sleeve 55 and gear 59to the right, with the gear 59 thereafter held in a precise position ofmeshing engagement with the driven gear 39.

Thus, when the clutch is disengaged the operator is free to turn thedriven gear 39, and the cylinders which are connected to it, into anapproximate condition of desired phasing with respect to the driveshaft, in other words, with respect to the cylinders of the associatedpress units. Then, when the clutch is engaged, a subsequent precisephasing adjustment may be made by rotating the nut 81.

Preferably, the pitch of the helical splines corresponds to the pitch ofthe helical teeth on the drive gear 59, with the splines and teeth beingoriented so that the endwise thrusts which are applied to the sleeve 55cancel one another. In other words, the axial thrust applied to thesplines 56 by the splines 53 is equal and opposite to the axial reactionthrust applied by the teeth 39 of the driven gear against the helicalteeth 59 on the sleeve. Thus, while the torque loading on the sleeve 55is high, the amount of force required to hold the sleeve 55 and gear 59in proper axial running position is relatively small. As a result, theprecise positioning of the gear 59, which is required for referencepurposes under running conditions, is achieved by use of a relativelylight bearing 101 and relatively light linkage 103, 104. In addition,there is no relative rotation between the cylinder and the horizontaldrive shaft when clutching, due to the fact that the splines and gearhave the same effective pitch, due ailowancebeing made for theirdifferent pitch diometers.

It will be apparent that the construction described above amply fulfillsthe objects set forth. Any desired degree of precision in phasingadjustment may be achieved and an adjustment may be made while the pressis running and while the effect of the adjustment upon the printedproduct is being observed. The same helical splines which result in therelative rotation of the drive gear with respect to the shaft whichdrives it are utilized to accommodate the clutching and unclutchingmovement of the drive gear. The structure is, nonetheless, simple andinherently long-lived.

Iclaim:

1. In a printing press having a single drive shaft and a plurality ofprinting units for acting in succession on a web of paper and eachhaving a bevel-type driven gear, a drive coupling interposed between thedrive shaft and driven gear comprising, in combination a first sleeveand a second sleeve telescoped over the shaft, said sleeves having ahelical spline connection between them, said first sleeve having aslidable keyed connection with the shaft and said second sleeve having abevel-type drive gear formed on one end thereof for drivingly engagingthe associated driven gear, said second sleeve having a shiftable yokeconnected thereto, means for shifting said yoke for positioning thedrive gear in a driving position in which the gears are meshed and aretracted position in which the gears are unmeshed so that the drivengear may be freely rotated to make gross changes in the phase posi tionthereof, said first sleeve having a positioning yoke connected theretowith means for blocking said positioning yoke against rotation, meansfor adjusting said positioning yoke for imparting to the sleeve slightaxial movement thereby to adjust the degree of engagement of the splineswhen the bevel gear is drivingly meshed with the driven gear to achievesmall changes in phase position of the gears with respect to the driveshaft.

2. The combination as claimed in claim 1 in which the posi tioning yokehas threaded means for achieving axial adjusting movement of the yoke.

3. The combination as claimed in claim 1 in which the positioning yokeis in the form of a collar blocked against rotation and being an opposedthrust bearing connection with the first sleeve, the collar beingthreaded and engaged for adjustment purposes by an axially captive nut.

4. The combination as claimed in claim 1 in which the helical splines onthe second sleeve are correspondingly angled in a direction opposite tothe helical teeth on the drive gear so that the endwise thrust appliedto the second sleeve by the helical spline is in a direction opposite tothe reaction thrust applied to the second sleeve by the helical teeth onthe driven gear resulting in a minimum of net thrust on the secondsleeve even under conditions of high-torque transmission.

5. In a drive for a printing press unit having a driven gear andplurality of cylinders including a plate cylinder, the combinationcomprising a drive shaft having first and second sleeves mountedthereon, the first sleeve being slidably keyed to the drive shaft andhaving a helical spline, said second sleeve being telescoped over thefirst sleeve and having a cooperating helical spline meshing with thespline on the first sleeve and having a bevel-type gear formed on oneend for drivingly meshing with the driven gear, means for shifting thesecond sleeve between an engaged position in which the bevel gear mesheswith the driven gear and a second position in which the bevel gear isretracted from the driven gear accompanied by relative movement at thesplines, and a positioning yoke in the form of a collar telescoped overthe first sleeve and coupled to it for movement in the axial direction,and normally adjustable means for axially positioning the yoke and hencethe degree of engagement of the splines to change the phase position ofthe gears with respect to the shaft.

* t i i 9

1. In a printing press having a single drive shaft and a plurality ofprinting units for acting in succession on a web of paper and eachhaving a bevel-type driven gear, a drive coupling interposed between thedrive shaft and driven gear comprising, in combination a first sleeveand a second sleeve telescoped over the shaft, said sleeves having ahelical spline connection between them, said first sleeve having aslidable keyed connection with the shaft and said second sleeve having abeveltype drive gear formed on one end thereof for drivingly engagingthe associated driven gear, said second sleeve having a shiftable yokeconnected thereto, means for shifting said yoke for positioning thedrive gear in a driving position in which the gears are meshed and aretracted position in which the gears are unmeshed so that the drivengear may be freely rotated to make gross changes in the phase positionthereof, said first sleeve having a positioning yoke connected theretowith means for blocking said positioning yoke against rotation, meansfor adjusting said positioning yoke for imparting to the sleeve slightaxial movement thereby to adjust the degree of engagement of the splineswhen the bevel gear is drivingly meshed with the driven gear to achievesmall changes in phase position of the gears with respect to the driveshaft.
 2. The combination as claimed in claim 1 in which the positioningyoke has threaded means for achieving axial adjusting movement of theyoke.
 3. The combination as claimed in claim 1 in which the positioningyoke is in the form of a collar blocked against rotation and being anopposed thrust bearing connection with the first sleeve, the collarbeing threaded and engaged for adjustment purposes by an axially captivenut.
 4. The combination as claimed in claim 1 in which the helicalsplines on the second sleeve are correspondingly angled in a directionopposite to the helical teeth on the drive gear so that the endwisethrust applied to the second sleeve by the helical spline is in adirection opposite to the reaction thrust applied to the second sleeveby the helical teeth on the driven gear resulting in a minimum of netthrust on the second sleeve even under conditions of high-torquetransmission.
 5. In a drive for a printing press unit having a drivengear and plurality of cylinders including a plate cylinder, thecombination comprising a drive shaft having first and second sleevesmounted thereon, the first sleeve being slidably keyed to the driveshaft and having a helical spline, said second sleeve being telescopedover the first sleeve and having a cooperating helical spline meshingwith the spline on the first sleeve and having a bevel-type gear formedon one end for drivingly meshing with the driven gear, means forshifting the second sleeve between an engaged position in which thebevel gear meshes with the driven gear and a second position in whichthe bevel gear is retracted from the driven gear accompanied by relativemovement at the splines, and a positioning yoke in the form of a collarteLescoped over the first sleeve and coupled to it for movement in theaxial direction, and normally adjustable means for axially positioningthe yoke and hence the degree of engagement of the splines to change thephase position of the gears with respect to the shaft.